What is the correct prim type in UsdShade for sharing reusable portions of shading networks,...

The correct UsdShade prim type is NodeGraph. NVIDIA’s Learn OpenUSD material introduces UsdShade as the schema family used for creating and binding materials, where materials store renderer-facing shading definitions. The OpenUSD UsdShade specification defines UsdShadeNodeGraph as the mechanism for packaging shading networks into reusable units. A node graph can contain shader nodes and nested node graphs, expose public inputs as an interface, provide outputs, and be referenced into larger networks as a reusable building block.

Option C is correct because NodeGraph is explicitly designed for reusable and parameterized shading-network structure. It allows a pipeline to encapsulate repeated shading logic while exposing only selected parameters to consuming materials or larger graphs. Option A is incorrect because SubNetwork is not the correct UsdShade prim type in OpenUSD. Option B is incorrect because a custom schema could theoretically define new data models, but it is not the standard UsdShade construct for reusable shader-network packaging. This aligns with Visualization → UsdShade, Materials, Shading Networks, NodeGraph Interfaces, Parameterization, and Reusable Material Components .